fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)

PATCH In review Fengguang Wu 3 participants 5 messages Aug 26, 2012 Kernel janitors

lore

Share & tools

lore

Fengguang Wu

author

2012-08-26 19:12 UTC #0 lore raw

PATCH 30/32 fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)

Hi Cyrill,

FYI, there are new sparse warnings show up in

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git master
head:   9283194882d18e3755c4ebc0b86db9f9a4f4c81a
commit: c8506285ded8009f7c1ab937fc0021c6294ba424 [30/32] procfs: Move /proc/pid/fd[info] handling code to fd.[ch]

All sparse warnings:

+ fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)
fs/proc/fd.c:87:55: expected unsigned int [unsigned] f_mode
fs/proc/fd.c:87:55: got restricted fmode_t [usertype] f_mode
+ fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer

vim +87 fs/proc/fd.c

    84				rcu_read_lock();
    85				file = fcheck_files(files, fd);
    86				if (file) {

Quoted 1 line

87 unsigned f_mode = file->f_mode;

    88	
    89					rcu_read_unlock();
    90					put_files_struct(files);

---
0-DAY kernel build testing backend Open Source Technology Centre
Fengguang Wu <[email protected]> Intel Corporation

Cyrill Gorcunov

2012-08-26 19:26 UTC #1 lore raw

Re: [vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base typ

Quoted 16 lines · Fengguang Wu

Hi Cyrill,
FYI, there are new sparse warnings show up in
tree:   git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git master
head:   9283194882d18e3755c4ebc0b86db9f9a4f4c81a
commit: c8506285ded8009f7c1ab937fc0021c6294ba424 [30/32] procfs: Move /proc/pid/fd[info] handling code to fd.[ch]
All sparse warnings:
+ fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)
fs/proc/fd.c:87:55: expected unsigned int [unsigned] f_mode
fs/proc/fd.c:87:55: got restricted fmode_t [usertype] f_mode
+ fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer

Quoted 8 lines

vim +87 fs/proc/fd.c

    84				rcu_read_lock();
    85				file = fcheck_files(files, fd);
    86				if (file) {

Quoted 1 line

87 unsigned f_mode = file->f_mode;

    88	
    89					rcu_read_unlock();
    90					put_files_struct(files);

Sigh. Thanks a lot, Fengguang! This routine has been moved from base.c (which had this nit already). Al, could you please make it unsigned int, and push fix intou your tree?

Cyrill

Cyrill Gorcunov

2012-08-26 19:52 UTC #2 lore raw

Re: [vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base typ

In reply to Fengguang Wu

Quoted 26 lines · Cyrill Gorcunov

Quoted 16 lines · Fengguang Wu
Hi Cyrill,
FYI, there are new sparse warnings show up in
tree:   git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git master
head:   9283194882d18e3755c4ebc0b86db9f9a4f4c81a
commit: c8506285ded8009f7c1ab937fc0021c6294ba424 [30/32] procfs: Move /proc/pid/fd[info] handling code to fd.[ch]
All sparse warnings:
+ fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)
fs/proc/fd.c:87:55: expected unsigned int [unsigned] f_mode
fs/proc/fd.c:87:55: got restricted fmode_t [usertype] f_mode
+ fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer
Quoted 8 lines
vim +87 fs/proc/fd.c
    84				rcu_read_lock();
    85				file = fcheck_files(files, fd);
    86				if (file) {
Quoted 1 line
87 unsigned f_mode = file->f_mode;
    88	
    89					rcu_read_unlock();
    90					put_files_struct(files);

Quoted 3 lines

Sigh. Thanks a lot, Fengguang! This routine has been moved from base.c (which had this nit already). Al, could you please make it unsigned int, and push fix intou your tree?

This should fix the problem (if needed, since the next commit in series should drop this declaration). Also this patch changes type for i_mode, which I think a good idea.
---
From: Cyrill Gorcunov <[email protected]>
Subject: fs, proc: Fix sparse warning in tid_fd_revalidate

The following warnings have been caught

 | + fs/proc/fd.c:87:55:  sparse: incorrect type in initializer (different base types)
 |   fs/proc/fd.c:87:55:  expected unsigned int [unsigned] f_mode
 |   fs/proc/fd.c:87:55:  got restricted fmode_t [usertype] f_mode
 | + fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer
 |   fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer

make f_mode and i_mode declared with proper types.

Reported-by Fengguang Wu <[email protected]>

Signed-off-by Cyrill Gorcunov <[email protected]>

CC Al Viro <[email protected]>

---
 fs/proc/fd.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6.git/fs/proc/fd.c =================================--- linux-2.6.git.orig/fs/proc/fd.c +++ linux-2.6.git/fs/proc/fd.c
@@ -84,7 +84,7 @@ static int tid_fd_revalidate(struct dent
rcu_read_lock();
file = fcheck_files(files, fd); if (file) {
- unsigned f_mode = file->f_mode;
+ unsigned int f_mode = file->f_mode;

rcu_read_unlock(); put_files_struct(files);
@@ -101,7 +101,7 @@ static int tid_fd_revalidate(struct dent
}

if (S_ISLNK(inode->i_mode)) {
- unsigned i_mode = S_IFLNK;
+ umode_t i_mode = S_IFLNK;
if (f_mode & FMODE_READ)
i_mode |= S_IRUSR | S_IXUSR;
if (f_mode & FMODE_WRITE)

Al Viro

2012-08-26 20:20 UTC #3 lore raw

Re: [vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base typ

In reply to Fengguang Wu

Review

Quoted 2 lines · Cyrill Gorcunov

(quoted diff) +1 -1

-				unsigned f_mode = file->f_mode;
+				unsigned int f_mode = file->f_mode;

This changes nothing; unsigned and unsigned int are exactly the same. fmode_t isn't, from sparse POV, and that's what you want to use here.

Cyrill Gorcunov

2012-08-26 20:40 UTC #4 lore raw

Re: [vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base typ

In reply to Fengguang Wu

Quoted 6 lines · Al Viro

Review
Quoted 2 lines · Cyrill Gorcunov
(quoted diff) +1 -1
-				unsigned f_mode = file->f_mode;
+				unsigned int f_mode = file->f_mode;
This changes nothing; unsigned and unsigned int are exactly the same. fmode_t isn't, from sparse POV, and that's what you want to use here.

True. I get messed with this warning. Please see updated below.
---
From: Cyrill Gorcunov <[email protected]>
Subject: fs, proc: Fix sparse warning in tid_fd_revalidate

The following warnings have been caught

 | + fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)
 |   fs/proc/fd.c:87:55:    expected unsigned int [unsigned] f_mode
 |   fs/proc/fd.c:87:55:    got restricted fmode_t [usertype] f_mode
 | + fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer
 |   fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer

make f_mode and i_mode declared with proper types.

Reported-by Fengguang Wu <[email protected]>

Signed-off-by Cyrill Gorcunov <[email protected]>

CC Al Viro <[email protected]>

---
 fs/proc/fd.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

rcu_read_unlock(); put_files_struct(files);
@@ -101,7 +101,7 @@ static int tid_fd_revalidate(struct dent
}

if (S_ISLNK(inode->i_mode)) {
- unsigned i_mode = S_IFLNK;
+ umode_t i_mode = S_IFLNK;
if (f_mode & FMODE_READ)
i_mode |= S_IRUSR | S_IXUSR;
if (f_mode & FMODE_WRITE)